Most boaters are having their boats winterized this time of year before the temperature falls below freezing.

Kent Adams, general manager of Willie's Marine, said the fall is an important time of year for boat owners.

"If they're not winterized properly the damage can be extensive," he said.

Scott Lawless, owner of Lawless Marine, said winterizing your boat is as important as filling it with fuel. Lawless flushes all fresh water from a boat, changes oil, and uses minus-20-degree antifreeze to get boats ready for the sometimes brutal Alaskan winter.

"You have an investment there and taking care of it now takes care of a lot of problems in the spring," Lawless said. "The most important thing for anybody is to make sure that they do winterize it."

Lawless said it is important to go to a reputable mechanic to make sure the work is done properly because of the potential cost of damage that can be caused by the winter.

"A lot of these boats that people are driving these days are definitely investments. They're not cute little toys now," he said.

Dean Dotson of Juneau Marine Services said he has seen extensive damage on boats left unattended in freezing conditions without being winterized.

"I've even seen frozen engine blocks that have cracked because they haven't taken the time to flush them out and put antifreeze in them," he said. "I think winterizing your engine is the thing that's going to make it so you can go out the next year."

Adams said having a place to store a boat for the winter is key to its longevity. If a covered area is unavailable, he said shrink-wrapping a boat is a good idea. They take 7 mm plastic and use a large flamethrower so it shrinks tightly around the boat and keeps moisture from penetrating, Adams said.

"If you're going to be away and not be able to tend to your boat, the shrink-wrap is your best option," he said.

Willie's Marine stores about 45 to 50 boats each winter, Adams said. He said a lot of people take good care of their boats during the winter, while others might not give enough attention to their boats.

"A lot of people have pretty sophisticated structures that they have built to store their boats in," he said.

Lawless said he is very busy winterizing boats this time of year. He said he winterizes around 40 boats each winter.

"Everybody waits to the last minute," he said. "Here pretty quick we get frost on the ground and it scares everybody a little bit."

Adams said it is important to make sure there is no fresh water left in the boat during the winter.

"Anywhere there's fresh water, get rid of it - completely," he said.

Adams said heads, holding tanks, water heaters and fresh water tanks have to be drained and filled with antifreeze to keep them from freezing and causing damage. If the exhaust manifolds aren't drained properly it will crack and let water into the engine," he said.

He said preventive maintenance is important for a boat's longevity, but doesn't solve all problems.

"The winterization process is probably the most important service you can do to your boat," Adams said. "Unfortunately, it still doesn't stop you from having problems in the spring."